Electric-current rectifier



Feb. 24, 1931. H. SHOEMAKER ELECTRIC CURRENT RECTIFIER 2 Sheets-Sheet 1 Filed Dec.

Patented Feb. 24, 1931 I UNITED STATES PATENT OFFICE HARRY SHOEMAKER, OF JERSEY CITY, NEW JERSEY, ASSIGNOB, B Y MESNT E ASSIGN- MENTS, TO I. B. MALLORY & INCORPORATED, OF INDIANAPOLIS, INDIANA, A.

CORPORATION .01 INDIANA ELECTRIC-CURRENT RECTIFIER Application filed December 31, 1928.. Serial No. 329,465.

This invention relates to electric current rectifiers, and more particularly to rectifiers of the dry surface cpntact variety, which rectify alternating currents of comparatively high voltages.

The object of the invention is to provide an improved construction and arrangement of parts, which is efficient, economical and readily manufactured.

More particularly it is an object of the invention to provide a device of the character specified which is rugged, both mechanically and electrically and adapted to rectify currents, preferably without the use of transformers, which have voltages substantially that of ordinar commercial magnitudes, such rectifiers being adapted to be connected for a variety of services where rectifying devices are to be employed.

Other objects of the invention will in part be obvious and will in part appear hereinafter. A

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts, which will be exemplified in the constructions hereinafter set forth and the scope of the application of which will be indicated in the claims. For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description 1 taken in connection with the accompanying drawings, if? which:

Fig. 1 is a view mainly in elevation, parts being broken away, showing a rectifying device constructed in accordance with the invention;

Fig. 2 is a vertical section of the rectifying device shown in- Fig. 1;

Fig. 3 is a horizontal sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a view, partly in plan and partly in section,showing features of the interior construction of the rectifying device;

Figs. 5 and 6 are views showing further details of construction; and

Figs. 7 and 8 are views, mainly diagrammatic, showing two forms of wiring connections which may be used in connection with devices of the presentinvention.

Referring now to the drawings, and particularly to Figs. 1 and 2, 10 denotes a base of inuslating material which is preferably of disc shape and is arranged to support the To accomplish readily the mounting of the rectifying columns upon the base 10 in this manner, a second relatively thin plate of insulating material 15, of suitable shape, is preferably interposed between the rectifying columns and the base 10 and has perforations in register with a plurality of recesses 1O in the base, which receive and hold against displacement the adjacent ends of columns 11, 12, 13 and 14. A supporting column or strut 16, of metal or other material adapted to withstand severe mechanical stresses, is then secured centrally upon the base 10. The rectifying columns are disposed equidistantly about the strut 16, the free end of the strut having a suitable securing means for holding the upper ends of the columns in posltion.

The means on the strut 16 for securing these rectifying columns is here shown as comprising a plate or disc 17of msulatm material, having a central opening 18 by w ch 1t lltS snugly over strut 16, this plate also having. a plurality of peripherally-dlsposed openings 19, which are engaged by the upper ends of the rectifying columns. To effect this engagement the rectifying columns are provided with projections on their ends, wh1ch are conveniently provided by assembling the rectlfying columns here shown on the rods 26, whlc pass centrally through the rectifying elements and extend somewhat beyond the ends of the columns. (lo-operating with the plate 17 there is a second plate 21 disposed above it and having perforations in register with those and the collar'22. Also there may be intergpsed at this point the end plate 25 of a cylinical housing '26, which is made to extend downwardly to a point substantially even with the bottom of the insulating base-1,0.

The strut 16 is here shown as secured to the baselO by means of a screw 27 which engages 1 with the strut from the under side of the base 10. There is also preferably interposed a sub-base or disc28 which serves not only as a washer for the screw 27, but as a means on which to mount conducting membersthat serve both as terminals and conductors for effecting the desired electrical connections between the rectifying columns and an external electrical system. A suitable arrangement of these terminals is illustrated in Figs. 1 and 2.

Fig. 5 shows details in the construction of disc 28. Here it is seen to have cruciform channels 29 cut across its top face, which are of a depth suflicient to have conducting clips I 30 disposed therein and lie flush with the surface of the disc, these clips being held in place by the rolled-over upper ends 31 of the conducting prongs 32, which engage frictionally with disc 28 and pass upwardly through the clips 30 for engagement therewith. The clips 30 each preferably have tongue-like members 33 that are bent to project upwardlyand be in register with openings 34 formed peripherally about the base 10. These tongues 33 conveniently project upwardly at points in the .base between the rectifying columns 11, 12, Band 14, since by such positions the electrical connectionsbetween the tongues and the rectifyingcolumns may-be made directly, whereby the prongs 32 serve as terminals through which the input and out ut connections are made to the rectifying evice when .constructed. The housing 26 is preferably provided with a series of ventilating openings 34 and 35 disposed respectively about the lower and upper ends, whereby sufficient air is permitted to circulate through the rectifying device to keep it cool under substantiallyall normal operating conditions. Additional openings, suchas shown at 36 in the top plate, may also be provided when desired.

The device of the present invention is designed primarily for the rectification of alternating currents of comparatively high voltages such as the commercial voltages had from lamp sockets and other commercial out-v lets, 'for example, a 60-cycle 110-volt, 01"

220-volt outlet. The rectifying columns here employed accordingly have a plurality of rectifying elements which are arranged in series relation and are taken in sufiicient number to be connected either as a single group across the source of current supply, or as a pluralitg of groups in series across such source.

convenient construction of the rectifying colhave relatively great mechanical strength.

Upon the disc 41 is disposed a washer 42, preferably of relatively soft metal so as to serve as a buffer element reacting against and absorbing compressional stresses. Upon washer 42 is disposed a second washer 43 of insulating material and upon this latter is dlsposed a terminal-conducting washer 44, which has a projecting prong 45 through which electrical connections are made as hereinafter described. Superposed upon the terminal washer 44 is one of the rectifying elements here shown as a perforated disc 46. This rec tifying element may be an electronegative electrode element of an asymmetric couple of the dry surface contact variety of the character set forth in Ruben application, Serial No. 113,009, filed June 1, 1926, and is of any suitable compound which is adapted to this end, for example, a composite metallic disc which has been exposed to sulphur vapors, or one of blue cupric sulphide as shown in Ruben Patent No. 1,649,741, dated November 15, 1927. Superposed upon disc 46 is a co-operating electrode element 47, also in disc form, which is a relatively thin disc of some electropositive metal, for example, aluminum or magnesium. Superposed upon the discs comprising the rectifying couple there is preferably disposed another bufier washer 48, which is substantially inert as to rectifying characteristics. superposed upon the washer 48 are the elements of a second rectifying couple, here denoted '46 and 47, respectively, together with another buffer washer 48?. Lead is a suitable material from which to make the buffer washers.

The column of rectifying elements is thus built up by adding superposed couples, with or without the associated buffer washers, until a sufiicient number of couples is in series to have impressed across its terminals the voltage which it is designed to employ. A rectifying column, when composed of magnesium-cupric sulphidecouples, is adapted to have impressed thereacross a potential difference which has approximately 2 volts per couple. The upper end of the column isshown as terminating in a pair of rectifying elements 46", 47 and a buffer washer 48", upon which is superposed a terminal washer 49, having a projecting prong 50, this terminal washer being held in place by the insulating washer 51. This latter is held under compression through a nut 52, which is in screw-threaded engagement with the upper of terminal prongs 32 and the-other two columns' 12 and 14 connected from one of the first pair of terminal prongs to an independent terminal prong 32, thereby leaving one of the original prongs dormant. Th1s arrangement of connections is indicated in Fig. 7 and is adapted for supplying rectified current to a system utilizing a center tap, such as shown at 61 on the reactive winding 62, the latter being connected across the power supply terminals of the circuit which supplies the load 63. Where this system of connections is adopted, the columns 11 and 13 have one pair of adjacent prongs of the terminalwashers electrically connected together', as indicated in Fig. 7 by the conductor 55. This is convemently effected in practice by turning the rectifying columns about their axes until such prongs come in contact, when they may be soldered or otherwise electrically connected as shown at 56 in Fig. 3. The prongs at the lower ends of the rectifying columns .11 and 13 are also turned so that they project against and are electrically connected to tongues 33 in order to effectconducting relation with the prongs 32 in-the base. The electrical connections between the lower terminal of the column 11 and the prong 32 are shown in Fig. 7 as accomplished by means of a, conductor indicated at 57. This'is effected in practice by turning the lower terminal washer so that its prong may be soldered or otherwise connected to an adjacent tongue 33, as shown at 58 in Figs. 2 and 3.

Where it is desired to connect the columns so that they are the four arms of a bridge circuit, the upper ends of adjacent columns are electrically connected together in pairs, while the lower ends are similarly'connected in pairs, but with alternate ones from those making the pairs for the upper-end connection. In this manner the four columns form the four sides of the bridge circuit, the prongs 32 being electrically connected to each of the junctions of the four sets of terminal prongs, as shown in Fig. 8, in which the rectifying system is connected across the supply terminals and 66 for supplying a load 67.

In operation it is seen that where the rectifying system employs; the center-tap connection and is connected across a 110-volt source of supply, as shown in Fig. 7, then substantially only one-half of the supply voltage isimpre'ssed across the load, so that the rectifying columns 11 and 13 (also the columns 12 and 14) require a total of twentytwo couples in series, on the assumption that the couples are of a character to withstand 2 volts each, i. e., if the columns be of equal length, then eleven couples are assembled in each column. Where, of course, it is desired to have a resultant voltage across the load which is more or less than this value acter indicated, the number of couples being increased or decreased for other voltages, as the case would require.

Thus it is seen that there is provided by the present invention a rectifyin device which is compact and occupies relatively little space, yet has rectifying elements sufficient to adapt it for rectifying alternating currents of relatively high voltages. The device also has mechanical strength sufficient to resist severe mechanical stress without interfering in any way with its operating char acteristics, and is also readily cooled so that its electrical characteristics are relatively constant under operating conditions.

By the present invention it is also seen that by keeping in stock a relatively small number of standard parts, rectifying devices for high voltage service may be assembled, which are adapted for operation in anxiety of different rectifying systems.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In dry rectifyingdevices and the like, the combination comprising a base, a supporting strut secured centrally to said base, securing means on the free end of said strut, a plurality of rectifying columns disposed in spaced relation about said strut, the ends of saidcolumns being secured respectively in said base and in said securing means, and conducting means comprising co-operating ductors of an external electrical system, a

parts on said base and on said columns adapted to connect the latter in a desired manner in an electrical rectifying system.

prising co-operating parts on said base and on said columns adapted for connecting the latter in a desired manner in an electrical rectifying system. I

3. In dry rectifying devices and the like, the combination comprising a base, a supporting strut secured centrally to said base, secur ing means on the free end of said strut, a plurality of rectifying columns each comprising a plurality of series-connected rectifying ele ments disposed equidistantly about said strut,

conducting terminal members on each of said columns, conductlng prongs on said base, the

prongs on said base and the terminal members on said columns being electrically connected in a manner whereby said rectifying device may be connected in a desired electrical rectifying system.

4. In dry rectifying devices and the like, the combination comprising an insulating base having a plurality of projecting prongs adapted to make electrical contact with consupporting strut centrally secured to said base' on the side opposite to that in which said'prongs extend, a securing plate secured to the free end of said strut, a plurality of rectifyingcolumns disposed equidistantly about said strut, said columns comprising a plurality of series-connected disc-type rectifying elements, the ends of said columnsbeing respectively secured in said base and in said supporting plate, conducting terminals at each end of said rectifying columns, and electrical connections between the prongs on said base and the terminals on said columns for connecting the same in a manner adapted for service in a desired electrical rectifying system- 5. In dry rectifying devices and the like, the combination comprising a base of an insulating disc, four projecting prongs supported by said disc and adapted to effect conducting relations with an external electrical circuit, a

supporting strut centrally secured to said disc,

a securing plate secured to the free end of said strut, four rectifying columns disposed equidistantly about said strut, said columns each comprising a plurality of series-connected dry-type rectifying elements secured under pressure and having projecting terminal prongs the ends of sai columns being secured prongs on said columns whereb the same are connected for service in a desired electrical rectifying system.

6. In dry rectifying devices and the like, i

the combination comprising a base of a disc of insulating material, a second disc disposed adjacentl to the first said disc and having four con ucting prongs extending away from the first said disc, asupporting strut disposed centrally on said base, and means for securing said discs and strut together, a securing plate on the free end of said strut, said base and securing plate each bein provided with four recesses disposed equi istantly about said strut, four rectifying columns, the ends of which are disposed in the recesses formed in said base and in said plate, said columns each comprising a plurality of series-connected dry-type rectifying elements retained under compression, projecting terminal prongs on said rectifying columns, and conducting means for electrically connecting the prongs on said base with the prongs on said columns for service in a desired electrical rectifying system. I

. 7 In dry rectifying devices and the like, the combination comprising a base of a disc of insulating material. a second disc of insulating material disposed adjacent the first said discand having four conducting prongs extending away from the first said disc, said prongs being secured to said second disc by means'of conducting clips having conducted tongues, the said tongues being arranged to extend through said first named disc, a supporting strut centrally disposed on said base,

means for securing said strut and said discs rigidly, a supporting plate secured on the free end of said strut, four recesses disposed about the periphery of said disc and said plate and equidistantly spaced from each other and from said strut, four rectifying columns, the ends of which are secured respectively in the recesses in. said base and in said plate, said columns each comprising a plurality of seriesconnected asymmetric couples of thedry surface contact variety secured under compression, conducting terminal washers at each end of said columns having projecting prongs, said prongs being electrically connected together and having electrical connectionsto said tongues whereby the rectifying columns are connected for service in a desired electrical system.

8. A rectifying column adapted for service in dry rectifying devices and the like, said column comprising a supporting rod, supporting discs on the ends of said rod, a stack of a plurality of perforated rectifying ele- -ments of the dry variety disposed for series operation about said rod between said supporting (11805 and retained under compression,

bufler washers distributed among said elements, terminal conductingiwashers disposed at the ends of said stac and insulating washers interposed between said terminal conducting Washers and said supporting discs. 9. A rectifying column adapted for service in dry rectifying devices and the like, said column comprising a supporting rod, adjustable supporting discs on the ends of said rod, a stack composed of a plurality of asymmetric 4 couples of the dry surface contact variety disposed for series operation about said rod, bufier washers of electrically inert conducting material disposed between each of said couples, terminal conducting washers having -'projecting prongs and making electrical contacts disposedat the ends of said stack, and v buiier washers insulatingly interposed between said terminal washers and said supporting discs, said discs being adjusted on said rod to retain-said stack rigidly under relatively high compression.

In testimony whereof I afiix 111 Si nature.

HARRY SHOE A ER. 

